Cabinet with rotatable and hydraulically liftable tabletop

ABSTRACT

A cabinet with a rotatable and hydraulically liftable tabletop uses a swivel means and at least one hydraulic cylinder to join a tabletop to a base cabinet. A second hydraulic cylinder additionally supports the tabletop above a caster that rolls along a circuit path about the cabinet such that the tabletop may be manipulated into a long table, tall table, or compact table configuration. The hydraulics may also be employed to lift the base cabinet off the ground such that the entire article of furniture may easily be moved like a push cart.

BACKGROUND OF THE INVENTION

The present invention relates generally to an article of furnituresuitable for the storage and use of audio-visual components used forpresentations, and more specifically to a cabinet having a moveablyjoined tabletop. Many of the rotatable tables in the prior art have asingle point of support that allows the table surface to be rotatedwithin reach of a user, such as the Lazy Susan and over-the-bed typetables shown and described in U.S. Pat. Nos. 3,963,288; 4,158,997;4,334,482 and 6,543,369. Heavier duty prior art cabinets having arotatable table require at least one leg support in addition to therotational support point, such as those shown and described in U.S. Pat.Nos. 5,005,925; 5,454,636 and 5,743,603, but they are not heightadjustable.

The ability to selectively position the height of a tabletop capable ofsupporting significant weight while maintaining the ability to rotatethe tabletop into various configurations relative to a base cabinetpresents some challenges. In U.S. Pat. No. 4,735,469, Liggettsidestepped the problem by placing the entire furniture assembly ontoheight adjustable legs having casters, but the entire assembly canaccidentally be moved if someone leans against it. Burdi et al.addressed the problem by simultaneously operating two drive assemblieswhile counting the number of rotations of each drive assembly so theheight change was consistent, as shown and described in U.S. Pat. No.6,286,441. The best solution seems to be the use of hydraulic lifts,such as those used with some medical and industrial tables, buthydraulic lifts can be damaged when they are twisted or improperlyloaded.

SUMMARY OF THE INVENTION

The present invention includes several unique combinations that providea tabletop that may be selectively positioned upwardly or downwardly andthat may be turned about an axis normal to a horizontal plane. Thetabletop is joined at one end to a base cabinet using a swivel means andat least one hydraulic cylinder, and the tabletop is joined at the otherend to a leg having at least another hydraulic cylinder atop a wheelsuch that the tabletop may be lifted and rotated relative to the basecabinet. A hydraulic pump that can force a liquid into the hydrauliccylinders is used to selectively adjust the height of the tabletop. Thearticle of furniture can be manipulated into a long table, tall table,or compact table configuration in addition to being rotatable andliftable into numerous other positions.

The most preferred embodiment of the present invention uses pairedhydraulic cylinders for extra stability and reliability. Additionally,the hydraulics may be used to lift the heavy base cabinet such that theentire article of furniture may be rolled on wheels when it is in thecompact table configuration. The features designed into the presentinvention make the article of furniture exceptionally well suited as apresentation desk that may be fully equipped with audio and visualdevices.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the most preferred embodiment of thearticle of furniture of the present invention in a long tableconfiguration.

FIG. 2 is a horizontal cross sectional view through line 2-2 in FIG. 1.

FIG. 3 is a plan view of the article of furniture of FIG. 1.

FIG. 4 is a vertical cross sectional view through line 4-4 in FIG. 3.

FIG. 5 is a perspective view of the article of furniture of FIG. 1 in atall table configuration that has been partially swiveled.

FIG. 6 is a perspective view of the article of furniture of FIG. 1 in acompact table configuration.

FIG. 7 is a plan view of the compact table configuration of FIG. 5.

FIG. 8 is a perspective view of the article of furniture of FIG. 5 withthe base cabinet lifted.

FIG. 9 is a cross sectional view of a first alternate swivel means.

FIG. 10 is a cross sectional view of a second alternate swivel means.

The following is the list of numerical callouts used in FIGS. 1-10:

-   -   10 base cabinet    -   12 top    -   14 back    -   16 first side    -   18 second side    -   20 tabletop    -   22 first half    -   24 second half    -   26 channel    -   30 Hydraulic pump    -   32 electric motor    -   34 switch    -   40 first hydraulic cylinder    -   42 second hydraulic cylinder    -   44 tube    -   46 rod    -   50 first leg framework    -   52 first leg cylinder bracket    -   54 first leg case    -   56 first leg access panel    -   58 turntable    -   60 second leg framework    -   62 second leg cylinder bracket    -   64 second leg case    -   66 second leg access panel    -   68 casters    -   70 sleeve    -   72 cylinder bracket    -   74 perpendicular mounting surface    -   76 swivel means    -   80 lifting member    -   82 handle    -   84 cabinet wheels

DETAILED DESCRIPTION OF THE INVENTION

The most preferred embodiment of the present invention, shown in FIGS. 1through 8, is a cabinet with a rotatable and hydraulically liftabletabletop. This description will describe the base cabinet, tabletop,swivel means and vertical adjustment means needed to make the presentinvention. The preferred embodiment's structure with optional featureswill be described first, followed by function and alternate embodiments.Preferred materials, shapes, methods of attachment and methods ofassembly will be discussed, but these preferences are not intended toexclude suitable or functionally equivalent alternatives. The term“join” has a broad meaning that is not limited to a direct connecting ofparts, so there may be intermediate parts that are not specificallynamed but that contribute to the joining of named parts. Unnamedbrackets, supports, framework and fasteners are assumed to be usedwhenever it should be obvious to an ordinarily skilled cabinet maker.

FIGS. 1-8, which are views of the most preferred embodiment, show a verybasic base cabinet 10. The base cabinet, like the majority of thearticle of furniture, is preferable made from a wood product or othersuitable cabinet making material. Because this article of furniture istypically used for presentations, a desk-sized structure made from aquality hardwood or veneer covered plywood having a beautiful finish ispreferred. The base cabinet includes a top 12, back 14, first side 16and second side 18. The first side serves as an at least one structurefor supporting the tabletop in a horizontal plane. The base cabinet'senclosure should be combined with any necessary article supportingmeans, not shown, such as drawers, racks, shelves, etc., fixed ormovable partly or wholly out of the enclosure to make an articlesupported more readily accessible. Additional components that may beadded include compartments, walls, doors, shelves, partitions, racks orother article supports, or similar parts of a compartment, fixed orremovable.

The tabletop 20 is a horizontally supported planar surface that isrigid, preferably a wood material. The tabletop has a first half 22 anda second half 24. The first half may be selected arbitrarily, such aswould be required for a round tabletop. The first half is joined to thefirst side 16 of the base cabinet 10 such that the base cabinet providesthe structure needed to at least partially support the tabletop in ahorizontal plane. The bottom surface of the tabletop includes a channel26, which could alternately be conduit or a cover, for concealing lines,wires or cables. The bottom surface of the tabletop may include mountingplates and brackets where extra strength is needed.

The tabletop 20 is hydraulically liftable by a vertical adjustment meansthat uses a hydraulic pump 30 that imparts motion to the tabletop when ameans for controlling the pump is operated, such as an electric motor 32that is actuated by a switch 34. An alternate means for controlling thepump is a simple hand crank. The hydraulic pump provides a fluidpressure that acts on a cross section of a rod or piston of one or morehydraulic cylinders. Hydraulic lines, not shown, extend from thehydraulic pump to each of the hydraulic cylinders. The hydraulic pumpand electric motor may be mounted to the back 14 of the base cabinet 10.An access panel may be used to hide the pump and motor from view.

There is a first hydraulic cylinder 40 that at least partially supportsthe first half 22 of the tabletop 20, and there is a second hydrauliccylinder 42 that at least partially supports the second half 24 of thetabletop. Hydraulic cylinders are often provided with a hydraulic pumpsuch that a system is fully charged when delivered, and the hydrauliccylinders are usually all identical. Most hydraulic cylinders areconstructed with a tube 44 and a rod 46. For hydraulic cylinders that donot maintain a good seal if the rod is rotated inside of the tube, wehave paired the first hydraulic cylinder with another hydraulic cylindersuch that the tubes of the first hydraulic cylinder and the anotherhydraulic cylinder are fixed relative to each other. This pairing ofhydraulic cylinders provides extra stability to the tabletop. For evenmore stability, the second hydraulic cylinder may be paired with yetanother hydraulic cylinder. The hydraulic pump and cylinders shown havea 12 inch (300 mm) height adjustment range, and were obtained throughMonarch Hyraulics, Inc., DynaLift® Group, located in Caledonia, Mich.

A first leg framework 50 is secured to the first side 16 of the basecabinet 10. In addition to providing a sturdy mounting surface, thefirst leg framework may be used to space the tabletop 20 away from thefirst side if there is a need for extra clearance to accommodate aparticular swivel means. The first hydraulic cylinder 40 is mounted tothe framework using a first leg cylinder bracket 52. A first leg case 54is used to hide the framework, bracket and cylinder, and a first legaccess panel 56 is provided for exposing the hydraulic cylinder formaintenance purposes.

The swivel means used in FIGS. 1-8 is a turntable 58 that makes thetabletop 20 rotatable relative to the base cabinet 10. The term “swivelmeans” includes, but is not limited to, turntables, ball jointassemblies, rollers, pins, tube and rod assemblies, sleeve and pinassemblies, wheel bearings and wheel bearing assemblies. The turntableshown is of the type commonly joined to the seat of a stool, but a wheelbearing assembly of the type commonly joined to a wheel on an automobileis a very robust alternative that may easily be adapted for use with thepresent invention by adding an appropriate bracket that provides amounting surface. The turntable swingably joins the tabletop to the basecabinet such that the tabletop is rotatable about an axis that isperpendicular to a horizontal plane. Some types of swivel means maybenefit from the addition of one or more rollers that function to reducethe freedom of movement of the tabletop. Rollers help prevent the axisabout which the tabletop rotates from being shifted by an appliedtorque, such as by someone sitting or leaning on an edge of thetabletop. If desired, the swivel means may be used to join the firsthydraulic cylinder to the first side of the base cabinet, therebyallowing the first hydraulic cylinder to be rotationally fixed relativeto the first half of the tabletop.

A second leg framework 60 is secured to an underside of the second half24 of the tabletop 20. The second hydraulic cylinder 42 is secured tothe second leg framework using a second leg cylinder bracket 62. Thesecond leg framework provides a sturdy mounting surface and spaces thesecond hydraulic cylinder away from the tabletop such that shorterhydraulic cylinders may be used without having to sacrifice any of theoverall desired height of the tabletop. A second leg case 64 and asecond leg access panel 66 protect the framework, bracket and cylinderfrom view. A rolling means, such as one or more casters 68, is fastenedto that end of the second hydraulic cylinder that is closest to thefloor or ground, preferably at the free end of the rod. If desired, thesecond leg framework may be fixed to the rolling means such that thesecond hydraulic cylinder separates the second leg framework from thetabletop, but the tabletop may not appear to be sturdy with increasedheight adjustment.

Because the hydraulic cylinders used in the preferred embodiment aredesigned to be used as a set of four, the first hydraulic cylinder hasbeen paired to another hydraulic cylinder, and the second hydrauliccylinder has also been paired to yet another hydraulic cylinder. Thesecond hydraulic cylinder and its paired cylinder each have their owncaster. The pair of casters is a rolling means. The casters mayalternatively be mounted to a bracket to increase the distance ofseparation between the casters, thereby increasing stability of thetabletop, but the function remains the same and the bracket may bemounted to more than one hydraulic cylinder.

The allowable movement of the article of furniture of the presentinvention permits the tabletop 20 to be oriented in various positionsabout the base cabinet 10. There is a long table configuration, shown inFIGS. 1-4, characterized by the first half 22 of the tabletop beingsubstantially adjacent the first side 16 of the base cabinet, andcharacterized by the height of the tabletop being substantially in aplane defined by the top 12 of the base cabinet. If the hydraulics areoperated to lift the tabletop, there is a tall table configuration,shown in FIG. 5, characterized by the tabletop being above andsubstantially parallel to the top of the base cabinet. With the tabletoplifted, the tabletop may be rotated into numerous positions relative tothe base cabinet. At about 180 degrees of rotation, there is a compacttable configuration, shown in FIGS. 6 and 7, characterized by thetabletop being in a position that is substantially over the top of thebase cabinet.

FIG. 8 shows yet another configuration that allows the entire article offurniture to be rolled like it is a push cart. There are at least twocabinet wheels 84 that continuously support the first side 16 of thebase cabinet 10. A handle 82, or a pair of handles, on the second sideof the base cabinet is provided. A lifting member 80 is secured to thesecond leg framework and/or bracket (which is fixed relative to thetabletop), and the lifting member projects toward the base cabinet. Inthe compact table configuration, the lifting member is directly belowthe handle. As the hydraulics are operated to lift the tabletop, thelifting member catches the handle before the maximum lift capacity ofthe hydraulic cylinders is reached, and the second side of the basecabinet is lifted off the ground slightly before the hydraulics reach amaximum upward adjustment of the height of the tabletop. Between thecabinet wheels under the first side and the casters 68 under the secondside 18 of the base cabinet, the entire article of furniture is onwheels. An alternate lifting member could be a pair of pins that passthrough the second leg framework and through apertures on the secondside 18 of the base cabinet to lock the unit into a compact tableconfiguration such that the pins will lift the cabinet via the aperturesas the hydraulics are operated.

FIG. 9 shows a first alternate swivel means that may be used with thepresent invention. There is only one first hydraulic cylinder, and it ischaracterized by a tube and a rod. The hydraulic cylinder is of the typethat allows the rod to turn inside of the tube without damaging theseals that keep the hydraulic fluid in the system. The free end of therod, opposite the end of the rod that interacts with the hydraulicfluid, is joined to the first half of the tabletop. The point ofattachment may be very close to the end of the table. Although the axisof rotation is shown to be somewhat centrally located along the end ofthe table, it could be moved toward one of the corners of a rectangulartabletop, such as the front corner on the first half. Also, to maintainthe compact table configuration, the axis of rotation relative to thebase cabinet may be moved toward a corner, such as the back corner ofthe second side.

FIG. 10 shows a second alternate swivel means 76 that includes a sleeve70 that may be used with the present invention. The term “sleeve”includes, but is not limited to, a tubular cylinder, a hollow pipe and abushing. The sleeve is fastened to the first side of the base cabinetsuch that a horizontal cross section provides a substantially circularopening. The first hydraulic cylinder of the second alternate swivelmeans is a pair of tube and rod type hydraulic cylinders that have theirtubes fixed to each other using a cylinder bracket 72, or two suchbrackets that are fastened to each other. The cylinder bracket extendsto an attached perpendicular mounting surface 74 that is joined to aswivel means, such as a turntable or ball joint, and the swivel means isjoined to the first side of the base cabinet using a platform orbracket. The rods are secured to the tabletop. Because the tubes arefixed to each other, the rods can only travel up and down in the tubes.The rods can't spin or otherwise rotate inside of the tubes. When thepair of tubes is inside of the sleeve, the pair of tubes can rotateabout the swivel means while being supported by the sleeve to maintain avertical axis of rotation for the tabletop.

While a preferred form of the invention has been shown and described, itwill be realized that alterations and modifications may be made theretowithout departing from the scope of the following claims.

1. An article of furniture comprising: a base cabinet having a back, afirst side and a second side; a tabletop having a first half and asecond half; a first hydraulic cylinder that at least partially supportsthe first half of the tabletop at least partially above the first sideof the base cabinet; a swivel means that joins the tabletop to the basecabinet; at least one wheel; a second hydraulic cylinder that at leastpartially supports the second half of the tabletop substantially abovethe at least one wheel; a hydraulic pump that can force a liquid intothe hydraulic cylinders; and a means for controlling the hydraulic pumpsuch that a user can adjust the height of the tabletop relative to thebase cabinet.
 2. The article of furniture of claim 1 wherein the firsthydraulic cylinder is characterized by a tube and a rod; and wherein theswivel means is characterized by an ability of the rod to turn inside ofthe tube.
 3. The article of furniture of claim 1 wherein at least partof the first hydraulic cylinder is fixed relative to the first side ofthe base cabinet; and wherein the swivel means is a turntable thatsubstantially joins the first half of the tabletop to the firsthydraulic cylinder.
 4. The article of furniture of claim 1 wherein atleast part of the first hydraulic cylinder is fixed relative to thefirst half of the tabletop; and wherein the swivel means is a turntablethat substantially joins the first hydraulic cylinder to the first sideof the base cabinet.
 5. The article of furniture of claim 1 furthercomprising at least one roller that functions to reduce the freedom ofmovement of the swivel means.
 6. The article of furniture of claim 1wherein the at least one wheel is a pair of casters.
 7. The article offurniture of claim 1 further comprising at least one additionalhydraulic cylinder that at least partially supports the tabletop.
 8. Anarticle of furniture comprising: a base cabinet having a back, a firstside, a second side and a top; a tabletop having a first half and asecond half; a first pair of hydraulic cylinders that at least partiallysupports the first half of the tabletop; a swivel means that joins thetabletop to the base cabinet; at least one rolling means; a second pairof hydraulic cylinders that at least partially supports the second halfof the tabletop substantially above the at least one rolling means; ahydraulic pump that can force a liquid into the hydraulic cylinders; anda means for controlling the hydraulic pump such that a user can adjustthe height of the tabletop relative to the base cabinet.
 9. The articleof furniture of claim 8 further comprising a long table configurationcharacterized by the first half of the tabletop being substantiallyadjacent the first side of the cabinet base, and by the height of thetabletop being substantially in a plane defined by the top of the basecabinet.
 10. The article of furniture of claim 8 further comprising atall table configuration characterized by the tabletop being at leastone hundred millimeters above and substantially parallel to the top ofthe base cabinet.
 11. The article of furniture of claim 8 furthercomprising a compact table configuration characterized by the tabletopbeing in a position that is substantially over the top of the basecabinet.
 12. The article of furniture of claim 11 further comprising atleast two wheels that support the first side of the base cabinet. 13.The article of furniture of claim 11 further comprising a handle on thesecond side of the base cabinet; a lifting member for joining the handleto the second half of the tabletop; and wherein an upward adjustment ofthe height of the tabletop causes the second side of the base cabinet tobe lifted by the lifting member when it is joined to the handle.
 14. Thearticle of furniture of claim 13 further comprising at least two wheelsthat support the first side of the base cabinet.
 15. The article offurniture of claim 8 wherein the at least one rolling means is a pair ofcasters.
 16. An article of furniture comprising: a base cabinet; atabletop; at least one hydraulic cylinder, characterized by a tube and arod, that at least partially supports the tabletop; a sleeve, fastenedto the base cabinet, that fits around at least part of the tube suchthat movement of the tube is substantially limited to rotationalmovement that causes the tabletop to swivel relative to the basecabinet; a hydraulic pump that can force a liquid into the at least onehydraulic cylinder; and a means for controlling the hydraulic pump suchthat a user can adjust the height of the tabletop relative to the basecabinet.
 17. The article of furniture of claim 16 further comprising aswivel means that is fastened to the base cabinet and that supportsweight distributed to the tube of the at least one hydraulic cylinder.18. The article of furniture of claim 16 wherein the sleeve is a hollowpipe.
 19. The article of furniture of claim 16 wherein the at least onehydraulic cylinder is a pair of hydraulic cylinders having their tubesjoined by a bracket.
 20. The article of furniture of claim 19 furthercomprising a swivel means that is fastened to the base cabinet and tothe bracket.